Transcript 18.1 Water in the Atmospherex

1.
2.
3.
4.
What layer of the atmosphere
contains ozone that filters UV
radiation?
On a map showing temperature
distributions, what are the lines
connecting points of equal
temperature?
What is the description of
atmospheric conditions over a long
period of time?
The bottom layer of the
atmosphere in which we live is
called the ____?
 Complete
the #5-8 on page 6 of the sheet
entitled, “Standardized Test Prep”. Answer
all questions to the best of your ability. You
may write on this sheet.
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Today, you will be able to:
Identify most important atmospheric gas.
• Describe change of state.
• Compare/Contrast the abilities of
cold/warm air to hold water vapor.
Define/Describe factors that affect the
relative humidity.
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 Water vapor is the source of all
condensation and precipitation.
 Precipitation is any form of water that falls
from a cloud.
 When it comes to understanding
atmospheric processes, water vapor is the
most important gas in the atmosphere.
 Solid to Liquid
• The process of changing state, such as melting
ice, requires that energy be transferred in the form
of heat.
• Latent heat is the energy absorbed or released
during a change in state.
 Liquid to Gas
• Evaporation is the process of changing a liquid to
a gas.
• Condensation is the process where a gas, like
water vapor, changes to a liquid, like water.
 Solid to Gas
• Sublimation is the conversion of a solid directly
to a gas without passing through the liquid state.
• Deposition is the conversion of a vapor directly
to a solid.
Which processes absorb heat?
Which processes release heat?
Give an everyday example of one of the processes shown.
 Humidity is a general term for the amount
of water vapor in air.
 Saturation
• Air is saturated when it contains the maximum
quantity of water vapor that it can hold at any
given temperature and pressure.
• When saturated, warm air contains more water
vapor than cold saturated air.
 Relative Humidity
• Relative humidity is a ratio of the air’s actual
water-vapor content compared with the amount
of water vapor air can hold at that temperature
and pressure.
• To summarize, when the water-vapor content of
air remains constant, lowering air temperature
causes an increase in relative humidity, and
raising air temperature causes a decrease in
relative humidity.
 Dew Point
• Dew point is the temperature to which a parcel of air
would need to be cooled to reach saturation.
 Measuring Humidity
• A hygrometer is an instrument to measure relative
humidity.
• A psychrometer is a hygrometer with dry- and wetbulb thermometers. A psychrometer is made of two
identical thermometers mounted side by side.
Evaporation of water from the wet bulb makes air
temperature appear lower than the dry bulb’s
measurement. The two temperatures are compared
to determine the relative humidity.
Dry-bulb
thermometer
Wet-bulb
thermometer
Change of
State
Sublimation
Solid  gas
Absorbed
Deposition
Gas  solid
Released
Condensation
Heat is …
Gas  liquid
Released
Evaporation
Liquid  gas
Absorbed
Melting
Solid  liquid
Absorbed
Freezing
Liquid  solid
Released
1. What are the 3 states of matter?
2. What is the change from a gas to
liquid called?
3. What will happen if air is heated by
the ground below it?